Haas, John M.: The holy and the good. The relationship between religion and morality in the thought of Rudolf Otto and Josef Pieper, Washington 1988, 300 S. (Diss).

Thomas, Anita J.: Sin and Self-Deception. A constructive statement using elements from the thought of Josef Pieper and from the philosophical and psychological discussion of self-deception, Southern Methodist University 1992 (Diss.).